In general, an automotive power steering system is an assist operating-force providing system configured to smoothly operate a steering handle at the time of great friction resistance applied by a steering wheel leading to a large operating-force for steering a steering handle. Size of the assistant operating-force assisting a steering of the steering handle may be determined by measuring torque applied to a torsion bar when steering a steering handle.
As an apparatus measuring torque of the steering handle, a torque measurement apparatus of several types of methodologies have been developed and used, but a low-priced magnetic field method having a fewer numbers of components is largely employed.
The steering angle measurement apparatus (module) includes a steering angle sensor, and this angle sensor measures a steering degree of the steering handle needed for control of an on-driving vehicle.
Also, the torque measurement apparatus (module) is mounted with a torque sensor, and the torque sensor measures torque applied to a torsion bar to smoothly manipulate a steering handle.
The overlaid angle sensor and torque sensor have separately modularized together with other composite members within an angle torque sensor assembly, that is, configured as an angle sensor module and a torque sensor module.
Conventionally, a torque sensor and an angle sensor for detecting the aforementioned steering torque and steering angle, respectively, are separately installed. Thus, a conventional torque measurement apparatus has a problem in that a component number increases and an installation process is complicated, leading to increase in manufacturing cost. Especially, the angle sensor has disadvantages of high manufacturing cost and cumbersome installation.